The disclosure of the following priority application is herein incorporated by reference: Japanese Patent Application No. 11-202035 filed Jul. 15, 1999.
1. Field of the Invention
The present invention relates to a display drive mechanism and a display apparatus for vehicle which slidingly move a display between a stored position and a projected position by the drive force of a motor.
2. Description of the Related Art
As a display apparatus for vehicle, there is a known type (for example, Japanese Laid open Utility Model Application No. Heisei 4-67550) which uses a display such as a liquid crystal monitor or the like embedded in a dashboard, and in which the display can be slidingly moved from the dashboard to a projected position.
With this type of sliding display apparatus it is necessary to maintain a high quality feeling in the operation of the display, while precluding the possibility of the display sinking down from its projected position under its own weight.
The objective of the present invention is to propose a display drive mechanism and a display apparatus for vehicle, in which a display can be moved with a high quality feeling.
Another objective of the present invention is to propose a display drive mechanism and a display apparatus for vehicle, in which the display does not sink down from its projected position under its own weight without a stopper.
The present invention is applied to a display drive mechanism for vehicle in which a display assembly is slidingly moved between a stored position and a projected position by the drive force of a motor.
The display drive mechanism for vehicle according to the first invention comprises a rotating body which is rotationally driven by the motor, a projecting portion which projects from either one of rotating body and display assembly, and a groove which is provided to the other of rotating body and display assembly and which is engaged with the projecting portion. The display assembly is driven to and fro in both directions between the stored position and the projected position by cam action of the projecting portion and the groove, as the rotating body rotates.
According to the first invention mentioned above, it is possible to provide a high quality feeling to the operation of the display with the minimum amount of mechanism, and without any requirement for fine control of the operation of the motor.
In particular, if the projecting portion is provided to the rotating body, while the groove is provided to the display assembly and extends in a direction perpendicular to the direction of sliding of the display assembly, then even if an external force is applied to the display assembly in the direction to push it towards its stored position, this force is not transformed into a force to rotate the motor in the opposite direction. Accordingly it is possible to prevent inadvertent movement of the display towards its stored position, without providing any particular lock mechanism.
It is preferable to provide mutually parallel first and second guide rods that guide the sliding of the display assembly, spaced apart along a first direction substantially perpendicular to the direction of projection of the projecting portion. In this constitution, the display drive mechanism for vehicle can be constituted as follows.
The first engaging portion on the display assembly engages with the first guide rod slidably in an axial direction of the rods in a state in which movement in the first direction is inhibited. A second engaging portion on the display assembly engages with the second guide rod slidably in an axial direction of the rods in a state in which movement in the first direction is permitted. The rotating body is disposed nearer to the first guide rod than to the second guide rod.
The display drive mechanism for vehicle according to the second invention comprises a pair of rotating bodies which are arranged along a direction perpendicular to the sliding direction of the display assembly and synchronously rotationally driven by the motor; a pair of projecting portions, each of which projects from each of rotating bodies at a position thereof eccentric to its center of rotation; and a pair of long grooves, each of which is provided to the display assembly and engaged with the projecting portion. The display assembly is driven to and fro in both directions between the stored position and the projected position by movement of each of the projecting portions in the groove, as the rotating body rotates in one rotational direction.
According to the second invention, since a pair of rotating bodies are provided and these are arranged along a direction perpendicular to the sliding direction of the display assembly, even if the display is quite wide no undue moment acts upon it, and thus the display can be driven smoothly. If the long groove extends substantially perpendicular to the sliding movement of the display assembly, it is possible to prevent inadvertent movement of the display towards its stored position, without providing any particular lock mechanism.
The display drive mechanism for vehicle according to the third invention is constituted as follows.
Mutually parallel first and second guide rods are provided and spaced apart along a first direction to guide the sliding of the display assembly. The first engaging portion on the display assembly engages with the first guide rod slidably in an axial direction of the rods in a state in which movement in the first direction is inhibited. The second engaging portion on the display assembly engages with the second guide rod slidably in an axial direction of the rods in a state in which movement in the first direction is permitted.
According to the third invention, even if a certain amount of dimensional deviation is present between the pair of guide rods and the engaging portions, it is possible to absorb this deviation without any sticking occurring between these members, and thereby the display can be driven smoothly.
The display assembly for vehicle according to the present invention is constituted of the above-noted display drive mechanism and a display assembly driven by the display drive mechanism.
The display assembly for vehicle according to another invention which slidingly moves the display assembly between the stored position and the projected position comprises a support member which supports the display drive mechanism in position, and a guide mechanism which is supported in position by the support member and guides the movement of the display assembly.
According to this invention, since a drive mechanism which transmits driving force to the display assembly and a guide mechanism which guides the movement of the display assembly are both supported in position by the common support member, thereby the positional accuracy between the two of them can be very high, and it is possible to suppress to a minimum level jerkiness, attributable to mounting inaccuracy, in the movement of the display unit.
In these display apparatus for vehicle, it is preferable that the substantially upper half portion of the screen of the display assembly is exposed from an installation surface at the stored position and an entire screen of the display assembly is exposed from the installation surface at the projected position. In this case, a movement amount of the display assembly is substantially half of a screen size of the display assembly in a movement direction of the display assembly.